Rockingham County, New Hampshire Natural Disaster Risk
FEMA National Risk Index assessment · NH
MediumComposite Risk Score
National percentile: 86th
Rockingham County faces medium composite natural disaster risk (NRI Risk Index score 85.8, 86th national percentile), driven primarily by coastal flood and ice storm exposure. Expected annual loss across all 18 hazard types is $90M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Rockingham County carries a medium composite natural disaster risk, with a National Risk Index score of 85.8 out of 100 — placing it in the 86th national percentile and near the national midpoint for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
The county's risk is driven primarily by coastal flood (seawater inundation from storm surge, high tides, and rising sea levels) at High risk — $12M in expected annual loss and about 8.03 events per year; ice storm (freezing rain that coats surfaces in heavy, damaging ice) at High risk — $2M in expected annual loss and about 2.03 events per year; and riverine flood (rivers and streams overflowing their banks after heavy rain or snowmelt) at Medium risk — $54M in expected annual loss and about 1.21 events per year. Across all hazards, FEMA estimates $90M in expected annual loss for a population of 314K.
Beyond physical exposure, Rockingham County has a very low social vulnerability rating (how susceptible the population is to harm) and a high community resilience rating (its capacity to prepare for and recover from disasters). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
History supports the rating: Rockingham County has received 35 federal disaster declarations since 1972, including 12 for severe storm events and 6 for snowstorm events. The most recent was Severe Winter Storm and Flooding (winter storm), declared in July 2024.
Among 10 New Hampshire counties, Rockingham County ranks #2 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Coastal Flood | High | 8.03 / yr | $12M |
| Ice Storm | High | 2.03 / yr | $2M |
| Riverine Flood | Medium | 1.21 / yr | $54M |
| Earthquake | Low | 0.00 / yr | $5M |
| Hurricane | Medium | 0.14 / yr | $5M |
| Drought | Medium | 5.59 / yr | $1M |
| Lightning | Medium | 19.84 / yr | $911K |
| Tornado | Medium | 0.12 / yr | $4M |
| Strong Wind | Medium | 0.84 / yr | $2M |
| Landslide | Low | 0.59 / yr | $11K |
| Winter Weather | Medium | 17.08 / yr | $169K |
| Heat Wave | Low | 4.22 / yr | $1M |
| Cold Wave | Low | 1.40 / yr | $2M |
| Wildfire | Very Low | 0.00 / yr | $64K |
| Hail | Low | 2.02 / yr | $226K |
| Avalanche | Very Low | 0.01 / yr | $3 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Rockingham County has received 35 federal disaster declarations since 1972, most recently Severe Winter Storm and Flooding in July 2024. Most frequent causes: Severe Storm (12), Snowstorm (6), Flood (5).
| Declared | Type | Disaster |
|---|---|---|
| July 2024 | Winter Storm | Severe Winter Storm and Flooding |
| April 2024 | Severe Storm | Severe Storms and Flooding |
| September 2023 | Flood | Severe Storms and Flooding |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| June 2018 | Snowstorm | Severe Winter Storm and Snowstorm |
| June 2018 | Coastal Storm | Severe Storm and Flooding |
| March 2015 | Severe Storm | Severe Winter Storm and Snowstorm |
| March 2013 | Severe Storm | Severe Winter Storm and Snowstorm |
| November 2012 | Hurricane | Hurricane Sandy |
Showing the 10 most recent of 35 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Rockingham County?
Rockingham County has a composite FEMA National Risk Index score of 85.8 out of 100, placing it in the Medium category and the 86th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Rockingham County?
The three highest-rated hazards are Coastal Flood (High, $12M EAL), Ice Storm (High, $2M EAL), Riverine Flood (Medium, $54M EAL). These account for most of the county's expected annual losses.
How does Rockingham County compare to other New Hampshire counties?
Rockingham County ranks #2 of 10 New Hampshire counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Rockingham County had?
FEMA records 35 federal disaster declarations for Rockingham County since 1972, most often 12 for severe storm events and 6 for snowstorm events. The most recent was Severe Winter Storm and Flooding, declared in July 2024.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Rockingham County's $90M EAL is a statistical average, not a guarantee for any specific year or address.